Self-contained filter assembly for magnetic deburring and polishing machine

ABSTRACT

A filter housing comprising an inlet and an outlet, an impeller positioned inside the filter housing magnetically coupled to a rotating magnetic field created by the magnetic disc when rotated by the motor, wherein rotation of the magnetic disc rotates the impeller which draws the solution through the inlet of the filter housing and push the solution out a first filter and out the outlet of the filter housing.

PRIORITY CLAIM

This application is a division of U.S. patent application Ser. No.17/392,967 filed Aug. 3, 2021, the contents of which are herebyincorporated by reference herein.

TECHNICAL FIELD

This invention relates to filters for use with polishing and deburringmachines, more specifically to a self-contained filter assembly for amagnetic deburring and polishing machine.

BACKGROUND INFORMATION

Metal workpieces have burrs that have been leftover during a mechanicalmachining process. Removal of such burrs helps to prevent injury toworkers and improves the appearance of the workpieces. The burrs left inthe side walls of holes or grooves of the metal workpieces, especiallyon some small workpieces, are removed by manual deburring one at a time.However, the whole procedure of manual deburring is both time and laborconsuming. This is especially true for small intricate parts. Inaddition, the workpieces are easily damaged during the manual deburringtreatment procedure.

In order to solve this problem, magnetic barrel tumblers have beendevised that polish workpieces by utilizing variations in the magneticfield occurring during the rotation of a magnetic disc attached withmagnets, water and a deburring solution. The workpieces are placed in anon-magnetic tub containing a media of magnetic particles, which removesharp edges by peening the surface until the burr falls off or the edgeis reshaped into a more rounded profile. The tub is positioned above amagnetic disc on a table top with a spacing underneath so that themagnet disc is out of contact with the bottom of the tub. The magnetdisc is then rotated at high speed.

The magnetic particles provided in the tub above the magnet disc may beslightly magnetized and attracted by the magnet disc. Since the magnetdisc is rotated at high speed, magnetic fields created by the rotatingmagnet disc momentarily alternate so that the magnetic abrasiveparticles or the permanent magnets are attracted to an approachingmagnetic field created by the magnet disc and so that a differentmagnetic field then approaches the magnetic abrasive particles of thepermanent magnets. Thus, the magnetic particles jump around andhelicopter inside and outside of every surface of the workpiecesremoving any burrs and polishing them in the process.

This process works well for most parts; however, parts made fromaluminum and stainless steel tend to blacken the water very quickly.This can cause the aluminum or stainless steel parts to have a tarnishedappearance.

Accordingly, there is a need for a filter assembly that will clean thewater during operation to prevent discoloration of the workpieces.

SUMMARY

In accordance with one aspect of the present invention, a magneticbarrel tumbler is provided with a motor, a magnetic disc attached to themotor, a plate positioned above the magnetic disc, and a tub positionedon top of the plate for receiving a solution, magnetic particles, andwork pieces. Inside the tub is a filter assembly comprising a filterhousing comprising an inlet and an outlet, an impeller positioned insidethe filter housing magnetically coupled to a rotating magnetic fieldcreated by the magnetic disc when rotated by the motor, wherein rotationof the magnetic disc rotates the impeller which draws the solutionthrough the inlet of the filter housing and push the solution out afirst filter and out the outlet of the filter housing.

The impeller can comprise a plurality of magnets that magneticallycouple the impeller to the rotating magnetic field. A plurality of slitsextend from the outer diameter of the impeller to a concentric throughhole with the number of slits corresponding to the number of magnets.

The filter assembly can further comprise an impeller housing for housingthe impeller. The impeller housing can be positioned between the inletof the filter housing and the first filter. The impeller housing cancomprise a lower cover comprising an opening aligned with the inlet ofthe filter housing, a top cover comprising an opening through whichfluid is pushed out of the impeller housing to the first filter. Theimpeller is positioned inside the impeller housing between the lowercover and the top cover with a space between an outer diameter of theimpeller and an inner wall of the impeller housing. Rotation of theimpeller draws fluid through the inlet of the filter housing andaccelerates the fluid toward the outer diameter of the impeller and outthe opening in the top cover to the first filter.

In an embodiment, a rod can hold the filter assembly together byextending from a top of the filter housing to a bottom of the filterhousing. One or more bearings can be positioned in the through hole ofthe impeller through which the rod extends.

In an embodiment, the opening of the top cover of the impeller housingcan extend into the through hole of the first filter such that solutionis pushed out the opening of the top cover of the impeller housing intothe through hole of the first filter and out the side of the firstfilter and out the out the outlet of the filter housing. A one-way valvecan be positioned on top of the opening in the top cover of the impellerhousing to prevent solution from flowing back into the impeller housing.

In an embodiment, the filter assembly can comprise a spacer near theinlet of the filter housing to raise the inlet of the filter housing asufficient distance off the bottom of the tub to receive solutionthrough the inlet of the filter housing yet block work pieces fromentering the inlet of the filter housing. In an embodiment, the heads ofscrews used to combine the impeller housing to the lower cover of thefilter assembly can be used as the spacer to raise the inlet off thebottom of the tub.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reading the following detailed description, takentogether with the drawings wherein:

FIG. 1 is a perspective view illustrating a magnetic barrel tumblercomprising a self-contained filter assembly in accordance with thepresent invention.

FIG. 2 is a perspective view illustrating the self-contained filterassembly of FIG. 1 .

FIG. 3 is a rearward-perspective exploded view of the self-containedfilter assembly of FIG. 2 .

FIG. 4 is a frontward-perspective exploded view of the self-containedfilter assembly of FIG. 2 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 , shown is a perspective view illustrating amagnetic barrel tumbler 10 comprising a filter assembly 100 inaccordance with the present invention. Magnetic barrel tumbler 10comprises of a motor frame 12 in which a motor 14 is placed. Attached toa shaft of motor 14 is a magnetic disc 16 that can be rotated at a highspeed by the motor 14. On the upper surface of magnetic disc 16 aredisposed N-polarity magnets 18 and S-polarity magnets 20 alternatinglyarranged around magnetic disc 16. A plate 22 that is non-magnetic isdisposed above magnetic disc 16 to provide separation between magneticdisc 16 and tub 24. Motor 14 can be an alternating current (AC) motor.The rotation speed of which can be freely controlled by a controllerplaced at the outer surface of motor frame 12.

Tub 24 receives magnetic particles comprising polishing pins, which canbe implemented as small stainless steel cylinders the size of which isadjusted depending on the application. A fluid is provided in the tub toprovide suspension of the workpieces. The fluid can be an aqueoussolution comprising of water and a deburring solution. Tub 24, which ismade of a non-magnetic material such as plastic, is positioned abovemagnetic disc 16 on top of plate 22 to provide spacing between themagnet disc 16 so that it is out of contact with the bottom of tub 24.Magnetic disc 16 is then rotated at high speed by motor 14.

The magnetic abrasive particles provided in tub 24 above magnet disc 16are slightly magnetized and are attracted to magnet disc 16. Sincemagnet disc 16 is rotated at high speed, magnetic fields created byrotating magnet disc 16 momentarily alternate so that magnetic abrasiveparticles are attracted to an approaching magnetic field created bymagnetic disc 16. As alternating different magnetic fields then approachmagnetic abrasive particles, they jump around and helicopter inside andoutside of every surface of the workpieces removing any burrs andpolishing them in the process.

Inside tub 24 is placed filter assembly 100 to filter the aqueoussolution to prevent discoloration of the workpieces, which is shown inFIGS. 2-4 . Filter assembly 100 uses an impeller 102 positioned inside afilter housing 104 that is magnetically coupled to a rotating magneticfield created by magnetic disc 16 to rotate impeller 102. Impeller 102draws the aqueous solution through an inlet 106 in the bottom of filterhousing 104 into filter assembly 100 and returns clean water outoutlet(s) 107 on the side of filter housing 104 back into tub 24.

More specifically, filter assembly 100 is cylindrically shaped andcomprises of filter housing 104 which has a lower cover 105 comprisingan inlet 106 and an outlet 107 configured as a plurality of holes aroundits side. A filter 108 is disposed inside filter housing 104 betweenimpeller 102 and outlet 107. In implementation, filter housing 104 canbe configured as cylindrical to correspond to a filter 108 that is alsocylindrically shaped to fit over the top thereof. Impeller 102positioned inside filter housing 104 is magnetically coupled to therotating magnetic field created by magnetic disc 16 to rotate impeller102 and draw fluid through inlet 106 of filter housing 104 and pushfluid out the plurality of holes that can define outlet 107 of filterhousing 104.

Impeller 102 can be formed of a solid piece of material with borescylindrically spaced around the perimeter to receive alternatingN-polarity magnets 110 and S-polarity magnets 112. Magnets 110, 112correspond with and are magnetically coupled to magnets 18, 20 inmagnetic disc 16. In this manner, the rotating reverse polarity ofmagnets 110, 112 with magnets 18, 20 causes impeller 102 to rotate. Aplurality of slits 114 can be formed in impeller 102 that extend from anouter diameter surface of impeller 102 to a concentric through hole 115through the center. These slits 114 form the blades of impeller 102.Rotational energy from the rotating impeller 102 increases the fluid'svelocity and pressure. The number of slits 114 can correspond with thenumber of magnets 110, 112.

Impeller 102 is positioned inside impeller housing 118, which ispositioned between inlet 106 of filter housing 104 and filter 108.Impeller housing 118 comprises of a lower cover 122 comprising anopening 124 aligned with inlet 106 of filter housing 104 and a top cover126 comprising an opening 128 through which fluid is pushed out ofimpeller housing 118 to filter 108. Impeller 102 can be cylindricallyshaped to fit inside impeller housing 118 also of cylindrical shape.Impeller 102 has an outer diameter surface which is less than aninternal diameter of impeller housing 118, or more specifically, of aninternal diameter of top cover 126 of impeller housing 118. This leavesa space between the outer diameter of impeller 102 and the inner wall oftop cover 126. Rotation of impeller 102 draws fluid through inlet 106 offilter housing 104 and accelerates the fluid to toward the outerdiameter of impeller 102 and out opening 128 in top cover 126 ofimpeller housing 118 to filter 108.

To assist in rotation of impeller 102 with respect to impeller housing118, one or more bearings 129 can be positioned inside hole 115 ofimpeller 102 with a spacer 131 to separate lower cover 122 and top cover126 from impeller 102.

In an embodiment, opening 128 in top cover 126 of impeller housing 118can be covered by a one-way valve 130 that allows fluid out of opening128 but not back through. In an embodiment, one-way valve 130 can beimplemented as a rubber gasket that moves upward when fluid isaccelerated out of opening 128 and retracts to cover opening 128 whenimpeller 102 slows down.

In an embodiment, a filter 134 can be positioned between inlet 106 offilter housing 104 and impeller 102 to filter fluid being drawn intoinlet 106 before it reaches impeller 102. This filter can be placedeither inside impeller housing 118 between lower cover 122 and impeller102, or, as shown outside of impeller housing 118 after lower cover 105for filter housing 104.

Inside filter assembly 100 is rod 133 that is used to lock the wholefilter assembly 100 together. Rod 133 can be connected at one end to acover 135 of filter housing 104 extend through filter 108 and impeller102, and connected to a lock nut 137 at its other end. Screws 132 areused to attach lower cover 105 to impeller housing 118.

Filter assembly 100 is positioned inside tub 24. In an embodiment, inlet106 is preferably on the bottom surface of filter assembly 100. In suchan embodiment, filter assembly needs to be elevated off the bottomsurface of tub 24. A spacer 131 near inlet 106 of filter housing 104raises inlet 106 off the bottom of tub 24 a sufficient distance toreceive fluid through inlet 106 yet block workpieces from entering inlet106 of filter housing 104.

In an embodiment, a plurality of screws 132 attach lower cover 105 ofthe filter housing 104 to impeller housing 118. The heads of screws 132can comprise spacer 131 to raise inlet 106 of filter housing 104 asufficient distance to receive fluid through inlet 106 yet blockworkpieces from entering inlet 106 of filter housing 104.

In operation, the spinning impeller 102 accelerates the water radiallyalong slits 114 creating a higher pressure around the outer diameter anda lower pressure at the center. The higher pressure is directed by theimpeller housing 118 to opening 128 at the top of impeller housing 118and into filter 108. The lower pressure at the center draws more waterthrough inlet 106. The diameter of impeller 102 is kept at a minimum tokeep the overall diameter of filter assembly 100 at a minimum so as tonot use too much of the tub, but still allow enough pressure to becreated to push the dirty water through filter assembly 100. The size ofslits 114 and number of slits 114 is designed to provide the correctflowrate needed to filter the water at around 3 gallons per minute inboth clockwise and counterclockwise operation. The number, position andsize of magnets 110, 112 must provide enough magnetic coupling toaccelerate impeller 102 and 3 gallons per minute of water.

While the principles of the invention have been described herein, it isto be understood by those skilled in the art that this description ismade only by way of example and not as a limitation as to the scope ofthe invention. Other embodiments are contemplated within the scope ofthe present invention in addition to the exemplary embodiments shown anddescribed herein. Modifications and substitutions by one of ordinaryskill in the art are considered to be within the scope of the presentinvention, which is not to be limited except by the following claims.

I claim:
 1. A filter assembly for a magnetic barrel tumbler, themagnetic barrel tumbler comprising a motor, a magnetic disc attached tothe motor, a plate positioned above the magnetic disc, and a tubpositioned on top of the plate for receiving a solution, magneticparticles, and work pieces, the filter assembly positionable in the tub,the filter assembly comprising: a filter housing, adapted to bepositioned in the tub of the magnetic barrel tumbler, comprising aninlet and an outlet; an impeller positioned inside the filter housingadapted to be magnetically coupled to a rotating magnetic field createdby a rotation of the magnetic disc by the motor of the magnetic barreltumbler to rotate the impeller and draw the solution through the inletof the filter housing and push the solution out the outlet of the filterhousing, wherein the impeller comprises a solid piece of material withan outer diameter wall, a concentric through hole, a plurality of borescylindrically spaced around a perimeter of the solid piece of material,and a plurality of slits extending from the outer diameter wall of theimpeller to the concentric through hole; a plurality of magnets each ofwhich is positioned in one of the plurality of bores in the impeller;and a first filter disposed between the impeller and the outlet of thefilter housing to filter the solution inside the tub of the magneticbarrel tumbler.
 2. The filter assembly of claim 1, wherein the pluralityof magnets are adapted to magnetically couple the impeller to therotating magnetic field created by the rotation of the magnetic disc bythe motor of the magnetic barrel tumbler.
 3. The filter assembly ofclaim 2, and further comprising an impeller housing positioned betweenthe inlet of the filter housing and the first filter for retaining theimpeller.
 4. The filter assembly of claim 3, wherein the impellerhousing further comprises: a lower cover comprising an opening alignedwith the inlet of the filter housing, a top cover comprising an openingthrough which the solution is pushed out of the impeller housing to thefirst filter, wherein the impeller is positioned inside the impellerhousing between the lower cover and the top cover with a space betweenthe outer diameter wall of the impeller and an inner wall of theimpeller housing, and wherein rotation of the impeller draws thesolution through the inlet of the filter housing and accelerates thesolution toward the outer diameter wall of the impeller and out theopening in the top cover to the first filter.
 5. The filter assembly ofclaim 1, wherein the plurality of slits corresponds to the plurality ofmagnets.
 6. The filter assembly of claim 4, and further comprising aone-way valve positioned between the opening in the top cover of theimpeller housing and the first filter.
 7. The filter assembly of claim6, wherein the one-way valve comprises a rubber gasket that moves upwardwhen the solution is accelerated out the opening in the top cover of theimpeller housing.
 8. The filter assembly of claim 3, and furthercomprising: a bearing positioned in the concentric through hole thatextends through the impeller; and a rod extending through the concentricthrough hole to combine the impeller housing to the filter housing. 9.The filter assembly of claim 1, and further comprising a second filterpositioned between the inlet of the filter housing and the impeller tofilter the solution being drawn into the inlet of the filter housingbefore it reaches the impeller.
 10. The filter assembly of claim 1, andfurther comprising a spacer near the inlet of the filter housing toraise the inlet of the filter housing a sufficient distance to receivethe solution through the inlet of the filter housing yet block the workpieces from entering the inlet of the filter housing.
 11. The filterassembly of claim 10, wherein the filter housing further comprises of alower cover and an outer cover; and wherein the filter assembly furthercomprises of an impeller housing for housing the impeller; and whereinthe spacer comprises a plurality of screws to attach the lower cover ofthe filter housing to the impeller housing, wherein each of theplurality of screws comprises a head which raise the inlet of the filterhousing the sufficient distance to receive the solution through theinlet of the filter housing yet block the work pieces from entering theinlet of the filter housing.
 12. The filter assembly of claim 11, andfurther comprising a second filter positioned between the lower cover ofthe filter housing and the impeller housing.
 13. The filter assembly ofclaim 8, wherein the rod extends through the bearing and combines a topof the filter housing to a bottom of the filter housing.
 14. The filterassembly of claim 13, wherein the plurality of magnets are positionedapart from the concentric through hole of the impeller and apart fromthe rod that extends through the bearing in the concentric through holeof the impeller.
 15. The filter assembly of claim 4, further comprisinga one-way valve positioned on top of the opening in the top cover of theimpeller housing to prevent the solution from flowing back into theimpeller housing.
 16. The filter assembly of claim 1, and furthercomprising a spacer on a bottom of the filter housing to raise the inletof the filter housing a sufficient distance off a bottom of the tub toreceive the solution through the inlet of the filter housing yet blockthe work pieces from entering the inlet of the filter housing.
 17. Thefilter assembly of claim 1, wherein the inlet of the filter housing isat a bottom of the filter housing and concentric with the impeller andthe outlet of the filter housing is at a side of the filter housingperpendicular to the inlet so that the impeller draws the solutionthrough the inlet at the bottom of the filter housing concentric withthe impeller and pushes the solution radially out the outlet of thefilter housing.
 18. The filter assembly of claim 17, wherein the outletof the filter housing is configured to be above a level of the solutionin the tub for the impeller to push the solution radially out the outletof the filter housing above the level of the solution in the tub. 19.The filter assembly of claim 18, wherein each of the plurality of slitsextend partially up the outer diameter wall and along a bottom surfaceof the solid piece of material to the concentric through hole in thesolid piece of material, wherein each of the plurality of slits arepositioned with a corresponding bore of the plurality of bores betweenadjacent slits.
 20. The filter assembly of claim 19, wherein theimpeller is positioned inside an impeller housing between a lower coverand a top cover with a space between the outer diameter wall of theimpeller and an inner wall of the impeller housing, and wherein rotationof the impeller draws the solution through the inlet of the filterhousing and accelerates the solution out the plurality of slits towardthe outer diameter wall of the impeller and out an opening in the topcover of the impeller housing to the first filter.